Mist: Both of these covers are cool, I love the big purple font of the UK cover but I like how it seems to be written in blood on the German cover, kind of a literal interpretation. As for choosing a favourite, I'm unsure, both have nice but nothing special backgrounds and the UK cover says more YA while the German cover leans towards horror. I think if I came across both in a shop the UK cover would be more likely to jump out at me so I'll choose that one.

Ninfa: Wow, the UK cover is really striking, I just love the purple title over the black and white picture, it has a great feeling and it's very eye-catching. Unfortunately it doesn't really represent the book as the German cover does, with the blood like font of the title, the German cover seems more appropriate and sort of "Texas chain massacre" style.
Personally I like the UK cover, but I can see how the German one would be more suited to the book...for me it's a tie this week.